Phosphonium compound, preparation method thereof, epoxy resin composition including the same, and semiconductor device prepared by using the same

ABSTRACT

A phosphonium compound, a method of preparing the same, an epoxy resin composition including the same, and a semiconductor device encapsulated with the same, the compound being represented by Formula 1:

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2015-0088742, filed on Jun. 22, 2015,in the Korean Intellectual Property Office, and entitled: “PhosphoniumCompound, Preparation Method Thereof, Epoxy Resin Composition Comprisingthe Same and Semiconductor Device Prepared by Using the Same,” isincorporated by reference herein in its entirety.

BACKGROUND

1. Field

Embodiments relate to a phosphonium compound, a method of preparing thesame, an epoxy resin composition including the same, and a semiconductordevice prepared using the same.

2. Description of the Related Art

Transfer molding is widely used as a method of packaging semiconductordevices, such as integrated circuits (ICs) and large scale integration(LSI) chips, with epoxy resin compositions to obtain semiconductordevices due to its advantages of low cost and suitability for massproduction. In transfer molding, modification of epoxy resins or phenolresins as curing agents may lead to an improvement in characteristicsand reliability of semiconductor devices.

Epoxy resin compositions may include an epoxy resin, a curing agent, acuring catalyst, and the like. As the curing catalyst, imidazolecatalysts, amine catalysts, and phosphine catalysts may be used.

SUMMARY

Embodiments are directed to a phosphonium compound, a method ofpreparing the same, an epoxy resin composition including the same, and asemiconductor device prepared using the same.

The embodiments may be realized by providing a phosphonium compoundrepresented by Formula 1:

wherein: R₁, R₂, R₃, and R₄ are each independently a substituted orunsubstituted C₁ to C₃₀ aliphatic hydrocarbon group, a substituted orunsubstituted C₆ to C₃₀ aromatic hydrocarbon group, or a substituted orunsubstituted C₁ to C₃₀ hydrocarbon group including a hetero atom; X andY are each independently a substituted or unsubstituted C₆ to C₃₀arylene group, a substituted or unsubstituted C₃ to C₁₀ cycloalkylenegroup, or a substituted or unsubstituted C₁ to C₂₀ alkylene group; R₅and R₆ are each independently hydrogen, a hydroxyl group, a C₁ to C₂₀alkyl group, a C₆ to C₃₀ aryl group, a C₃ to C₃₀ heteroaryl group, a C₃to C₁₀ cycloalkyl group, a C₃ to C₁₀ heterocycloalkyl group, a C₇ to C₃₀arylalkyl group, or a C₁ to C₃₀ heteroalkyl group.

R₁, R₂, R₃, and R₄ may each be independently a substituted orunsubstituted C₆ to C₃₀ aryl group.

At least one of R₁, R₂, R₃, and R₄ may be a hydroxyl group-substitutedC₆ to C₃₀ aryl group.

The phosphonium compound may be represented by one of the followingFormulae 1a to 1h.

The embodiments may be realized by providing a method of preparing aphosphonium compound, the method comprising reacting a phosphoniumcation-containing compound represented by Formula 2 with aphenylene-bis-benzamide anion-containing compound represented by Formula3:

wherein, in Formula 2, R₁, R₂, R₃, and R₄ are each independently asubstituted or unsubstituted C₁ to C₃₀ aliphatic hydrocarbon group, asubstituted or unsubstituted C₆ to C₃₀ aromatic hydrocarbon group, or asubstituted or unsubstituted C₁ to C₃₀ hydrocarbon group including ahetero atom, and M is a halogen, and wherein, in Formula 3, X and Y areeach independently a substituted or unsubstituted C₆ to C₃₀ arylenegroup, a substituted or unsubstituted C₃ to C₁₀ cycloalkylene group, ora substituted or unsubstituted C₁ to C₂₀ alkylene group; R₅ and R₆ areeach independently hydrogen, a hydroxyl group, a C₁ to C₂₀ alkyl group,a C₆ to C₃₀ aryl group, a C₃ to C₃₀ heteroaryl group, a C₃ to C₁₀cycloalkyl group, a C₃ to C₁₀ heterocycloalkyl group, a C₇ to C₃₀arylalkyl group, or a C₁ to C₃₀ heteroalkyl group; and Z is an alkalimetal or Ag.

The embodiments may be realized by providing an epoxy resin compositionincluding an epoxy resin, a curing agent, an inorganic filler, and acuring catalyst, wherein the curing catalyst includes the phosphoniumcompound according to an embodiment.

The epoxy resin may include at least one of a bisphenol A epoxy resin, abisphenol F epoxy resin, a phenol novolac epoxy resin, a tert-butylcatechol epoxy resin, a naphthalene epoxy resin, a glycidylamine epoxyresin, a cresol novolac epoxy resin, a biphenyl epoxy resin, a linearaliphatic epoxy resin, a cycloaliphatic epoxy resin, a heterocyclicepoxy resin, a Spiro ring-containing epoxy resin, a cyclohexanedimethanol epoxy resin, a trimethylol epoxy resin, and a halogenatedepoxy resin.

The curing agent may include a phenol resin.

The curing agent may include at least one of a phenol aralkyl phenolresin, a phenol novolac phenol resin, a xyloc phenol resin, a cresolnovolac phenol resin, a naphthol phenol resin, a terpene phenol resin, apolyfunctional phenol resin, a dicyclopentadiene-based phenol resin, anovolac phenol resin synthesized from bisphenol A and resorcinol, apolyhydric phenolic compound, an acid anhydride, and an aromatic amine.

The curing catalyst may be present in the epoxy resin composition in anamount of about 0.01 wt % to about 5 wt %, in terms of solid content.

The phosphonium compound may be present in the curing catalyst in anamount of about 10 wt % to about 100 wt %, based on a total weight ofthe curing catalyst.

The epoxy resin composition may have a curing shrinkage rate of lessthan about 0.40%, as calculated according to Equation 1:

Curing shrinkage=(|C−D|/C)×100  Equation 1

wherein, in Equation 1, C is a length of a specimen obtained by transfermolding the epoxy resin composition at 175° C. under a load of 70kgf/cm², and D is a length of the specimen after post-curing thespecimen at 170° C. to 180° C. for 4 hours and cooling.

The epoxy resin composition may have a storage stability after 72 hoursof about 85% or more, as calculated according to Equation 2:

Storage stability=(F1/F0)×100  Equation 2

wherein, in Equation 2, F1 is a flow length in inches of the epoxy resincomposition, measured after storing the composition at 25° C./50% RH for72 hours, using a transfer molding press at 175° C. and 70 kgf/cm² inaccordance with EMMI-1-66, and F0 is an initial flow length in inches ofthe epoxy resin composition.

The embodiments may be realized by providing a semiconductor deviceencapsulated with the epoxy resin composition according to anembodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will be apparent to those of skill in the art by describing indetail exemplary embodiments with reference to the attached drawings inwhich:

FIG. 1 illustrates a cross-sectional view of a semiconductor deviceaccording to one embodiment.

FIG. 2 illustrates a cross-sectional view of a semiconductor deviceaccording to another embodiment.

FIG. 3 illustrates a cross-sectional view of a semiconductor deviceaccording to a further embodiment.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey exemplary implementations to those skilled in the art.

In the drawing figures, the dimensions of layers and regions may beexaggerated for clarity of illustration. It will also be understood thatwhen a layer or element is referred to as being “on” another layer orelement, it can be directly on the other layer or element, orintervening layers may also be present. Like reference numerals refer tolike elements throughout.

As used herein, the term “substituted” in “substituted or unsubstituted”means that at least one hydrogen atom in the corresponding functionalgroup is substituted with a hydroxyl group, a halogen atom, an aminogroup, a nitro group, a cyano group, a C₁ to C₂₀ alkyl group, a C₁ toC₂₀ haloalkyl group, a C₆ to C₃₀ aryl group, a C₃ to C₃₀ heteroarylgroup, a C₃ to C₁₀ cycloalkyl group, a C₃ to C₁₀ heterocycloalkyl group,a C₇ to C₃₀ arylalkyl group, or a C₁ to C₃₀ heteroalkyl group. The term“halo” means fluorine, chlorine, iodine or bromine.

As used herein, the term “aryl group” refers to a substituent in whichall elements in the cyclic substituent have p-orbitals and thep-orbitals form a conjugated system. Aryl groups include mono- orfused-functional groups (namely, rings of carbon atoms which shareadjacent electron pairs). The term “unsubstituted aryl group” refers toa monocyclic or fused polycyclic C₆ to C₃₀ aryl group. Examples ofunsubstituted aryl groups may include phenyl groups, biphenyl groups,naphthyl groups, naphthol groups, and anthracenyl groups, without beinglimited thereto.

As used herein, the term “heteroaryl group” means a C₆ to C₃₀ aryl groupin which a ring comprises carbon atoms and 1 to 3 heteroatoms selectedfrom nitrogen, oxygen, sulfur and phosphorus. Examples of heteroarylgroups may include, but are not limited to, pyridinyl, pyrazinyl,pyrimidyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl,quinoxalinyl, acridinyl, quinazolinyl, cinnolinyl, phthalazinyl,thiazolyl, benzothiazolyl, isoxazolyl, benzisoxazolyl, oxazolyl,benzoxazolyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, purinyl,thiophenyl, benzothiophenyl, furanyl, benzofuranyl, and isobenzofuranyl.

As used herein, the term “hetero” in “heterocycloalkyl group”,“heteroaryl group”, “heterocycloalkylene group”, and “heteroaryllenegroup” refers to an atom selected from nitrogen, oxygen, sulfur, orphosphorus.

According to an embodiment, a phosphonium compound may include, e.g., aphosphonium cation and an anion having a hydroxyl group and an amidegroup at the same time. In an implementation, the phosphonium compoundmay be represented by the following Formula 1.

In Formula 1, R₁, R₂, R₃, and R₄ may each independently be or include,e.g., a substituted or unsubstituted C₁ to C₃₀ aliphatic hydrocarbongroup, a substituted or unsubstituted C₆ to C₃₀ aromatic hydrocarbongroup, or a substituted or unsubstituted C₁ to C₃₀ hydrocarbon groupincluding a hetero atom. X and Y may each independently be or include,e.g., a substituted or unsubstituted C₆ to C₃₀ arylene group, asubstituted or unsubstituted C₃ to C₁₀ cycloalkylene group, or asubstituted or unsubstituted C₁ to C₂₀ alkylene group. R₅ and R₆ mayeach independently be, e.g., hydrogen, a hydroxyl group, a C₁ to C₂₀alkyl group, a C₆ to C₃₀ aryl group, a C₃ to C₃₀ heteroaryl group, a C₃to C₁₀ cycloalkyl group, a C₃ to C₁₀ heterocycloalkyl group, a C₇ to C₃₀arylalkyl group, or a C₁ to C₃₀ heteroalkyl group. In an implementation,R₅ and R₆ may each independently be or include, e.g., hydrogen, ahydroxyl group, a substituted or unsubstituted C₁ to C₂₀ alkyl group, asubstituted or unsubstituted C₆ to C₃₀ aryl group, a substituted orunsubstituted C₃ to C₃₀ heteroaryl group, a substituted or unsubstitutedC₃ to C₁₀ cycloalkyl group, a substituted or unsubstituted C₃ to C₁₀heterocycloalkyl group, a substituted or unsubstituted C₇ to C₃₀arylalkyl group, or a substituted or unsubstituted C₁ to C₃₀ heteroalkylgroup.

In an implementation, in Formula 1, R₁, R₂, R₃, and R₄ may be asubstituted or unsubstituted C₆ to C₃₀ aryl group.

In an implementation, in Formula 1, at least one of R₁, R₂, R₃, and R₄may be a hydroxyl group-substituted C₆ to C₃₀ aryl group.

In an implementation, the phosphonium compound represented by Formula 1may be represented by one of the following Formulae 1a to 1h.

In an implementation, the phosphonium compound may have a melting pointof about 100° C. to about 130° C., e.g., 120° C. to 125° C. Thephosphonium compound may be water-insoluble. Within this range, thephosphonium compound may be cured at low temperature.

The phosphonium compound may be added to a composition including atleast one of an epoxy resin, a curing agent, and an inorganic filler soas to be used as a latent curing catalyst.

The phosphonium compound may help provide an epoxy resin compositionthat is capable of accelerating curing of an epoxy resin and a curingagent and that is capable of securing low temperature curability andhigh storage stability while minimizing viscosity change in a mixtureincluding the epoxy resin, the curing agent, and the like within desiredranges of time and temperature. Storage stability refers to the abilityto catalyze curing only at a desired curing temperature without anycuring activity at temperature deviating from a desired curingtemperature range. As a result, it is possible to store the epoxy resincomposition for a long time without viscosity change. Generally,proceeding of curing reaction may cause increase in viscosity anddeterioration in flowability when the epoxy resin composition is liquid,and may exhibit viscosity when the epoxy resin composition is solid.

The phosphonium compound may be prepared by, e.g., reacting aphosphonium cation-containing compound represented by Formula 2 with aphenylene-bis-benzamide anion-containing compound represented by Formula3.

In Formula 2, R₁, R₂, R₃, and R₄ may each independently be or include,e.g., a substituted or unsubstituted C₁ to C₃₀ aliphatic hydrocarbongroup, a substituted or unsubstituted C₆ to C₃₀ aromatic hydrocarbongroup, or a substituted or unsubstituted C₁ to C₃₀ hydrocarbon groupincluding a hetero atom. M may be, e.g., a halogen.

In Formula 3, X and Y may each independently be or include, e.g., asubstituted or unsubstituted C₆ to C₃₀ arylene group, a substituted orunsubstituted C₃ to C₁₀ cycloalkylene group, or a substituted orunsubstituted C₁ to C₂₀ alkylene group; R₅ and R₆ are each independentlyhydrogen, a hydroxyl group, a C₁ to C₂₀ alkyl group, a C₆ to C₃₀ arylgroup, a C₃ to C₃₀ heteroaryl group, a C₃ to C₁₀ cycloalkyl group, a C₃to C₁₀ heterocycloalkyl group, a C₇ to C₃₀ arylalkyl group, or a C₁ toC₃₀ heteroalkyl group. Z may be, e.g., an alkali metal or Ag.

The halogen may include, e.g., fluorine, chlorine, bromine, or iodine.The alkali metal may include, e.g., lithium, sodium, potassium,rubidium, cesium, francium, or the like.

The phosphonium cation-containing compound may be prepared by, e.g.,reacting a phosphine compound with an alkyl halide, an aryl halide, oran aralkyl halide in the presence of a solvent. The phosphoniumcation-containing compound may be present in a phosphoniumcation-containing salt. The phenylene-bis-benzamide anion-containingcompound may be present in a phenylene-bis-benzamide anion-containingsalt. Examples of the phosphine compound may include triphenylphosphine,methyldiphenylphosphine, dimethylphenylphosphine,ethyldiphenylphosphine, diphenylpropylphosphine,isopropyldiphenylphosphine, and diethylphenylphosphine.

The reaction between the compounds of Formulae 2 and 3 may be performedin an organic solvent, e.g., methanol, methylene chloride, acetonitrile,N,N-dimethylformamide, and toluene. The reaction may be performed bymixing the compounds of Formulae 2 and 3. Reaction between a phosphinecompound and an alkyl halide, an aryl halide, or an aralkyl halide mayproduce the phosphonium cation-containing compound, which may be addedto a phenylene-bis-benzamide anion-containing compound without anadditional separation process.

In accordance with an embodiment, an epoxy resin composition mayinclude, e.g., an epoxy resin, a curing agent, inorganic fillers, and acuring catalyst.

Epoxy Resin

In an implementation, the epoxy resin may have two or more epoxy groupsper molecule. Examples of epoxy resins may include bisphenol A typeepoxy resins, bisphenol F type epoxy resins, phenol novolac type epoxyresins, tert-butyl catechol type epoxy resins, naphthalene type epoxyresins, glycidyl amine type epoxy resins, cresol novolac type epoxyresins, biphenyl type epoxy resins, linear aliphatic epoxy resins,cycloaliphatic epoxy resins, heterocyclic epoxy resins, spiroring-containing epoxy resins, cyclohexane dimethanol type epoxy resins,trimethylol type epoxy resins, and halogenated epoxy resins. These epoxyresins may be used alone or in combination thereof. In animplementation, the epoxy resins may have two or more epoxy groups andone or more hydroxyl groups per molecule. In an implementation, theepoxy resins may include at least one of solid phase epoxy resins andliquid phase epoxy resins. In an implementation, the solid phase epoxyresin may be used.

In an implementation, the epoxy resin may be a biphenyl type epoxy resinrepresented by Formula 4 or a phenol aralkyl type epoxy resinrepresented by Formula 5.

In Formula 4, each R may independently be, e.g., a C₁ to C₄ alkyl group,and n may be, e.g., 0 to 7 on average.)

In Formula 5, n may be, e.g., 1 to 7 on average.)

In an implementation, the composition may include the epoxy resin in anamount of about 2 wt % to about 17 wt %, e.g., about 3 wt % to about 15wt % or about 3 wt % to about 12 wt % in terms of solid content (e.g.,based on a total weight of the composition). Within this range, thecomposition may help secure curability.

Curing Agent

The curing agent may include, e.g., phenolaralkyl type phenol resins,phenol novolac type phenol resins, xyloc type phenol resins, cresolnovolac type phenol resins, naphthol type phenol resins, terpene typephenol resins, multifunctional phenol resins, dicyclopentadiene-basedphenol resins, novolac type phenol resins synthesized from bisphenol Aand resol, polyhydric phenol compounds (e.g., tris(hydroxyphenyl)methaneand dihydroxybiphenyl), acid anhydrides (e.g., maleic anhydride andphthalic anhydride), aromatic amines (e.g., meta-phenylenediamine,diaminodiphenylmethane, and diaminodiphenylsulfone), or the like. In animplementation, the curing agent may include, e.g., a phenol resinhaving one or more hydroxyl groups.

In an implementation, the curing agent may be, e.g., a xyloc type phenolresin represented by Formula 6 or a phenolaralkyl type phenol resinrepresented by Formula 7.

In Formula 6, n may be, e.g., 0 to 7 on average.

In Formula 7, n may be, e.g., 1 to 7 on average.

In an implementation, the curing agent may be present in the epoxy resincomposition in an amount of about 0.5 wt % to about 13 wt %, e.g., about1 wt % to about 10 wt % or about 2 wt % to about 8 wt % in terms ofsolid content. Within this range, the epoxy resin composition can securecurability.

Inorganic Filler

The epoxy resin composition may further include an inorganic filler. Theinorganic filler may help improve mechanical properties of the epoxyresin composition while reducing stress in the epoxy resin composition.Examples of the inorganic filler may include fused silica, crystallinesilica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay,talc, calcium silicate, titanium oxide, antimony oxide, and glassfibers.

In an implementation, fused silica having a low coefficient of linearexpansion may be used, in view of stress reduction. The fused silicarefers to amorphous silica having a specific gravity of 2.3 or less. Thefused silica may be prepared by melting crystalline silica or mayinclude amorphous silica products synthesized from various rawmaterials. In an implementation, the inorganic filler may include about40 wt % to about 100 wt % of a fused silica mixture, based on the totalweight of the inorganic fillers, wherein the fused silica mixtureincludes about 50 wt % to about 99 wt % of spherical fused silica havingan average particle diameter of about 5 μm to about 30 μm and about 1 wt% to about 50 wt % of spherical fused silica having an average particlediameter of about 0.001 μm to about 1 μm. In an implementation, theinorganic filler may be adjusted to a maximum particle diameter of about45 μm, about 55 μm or about 75 μm, depending upon application of theepoxy resin composition. Although the spherical fused silica may includeconductive carbon as a foreign substance on the surface of silica, thespherical fused silica may incorporate a smaller amount of polar foreignsubstances.

The inorganic filler may be present in an appropriate amount dependingupon desired physical properties of the epoxy resin composition, e.g.,moldability, low-stress properties, and high-temperature strength. In animplementation, the inorganic filler may be present in an amount ofabout 70 wt % to about 95 wt %, e.g., about 75 wt % to about 92 wt %, inthe epoxy resin composition (e.g., in terms of solid content). Withinthis range, the epoxy resin composition may help secure good flameretardancy, flowability, and reliability.

Curing Catalyst

The epoxy resin composition may include a curing catalyst including thephosphonium compound represented by Formula 1. In an implementation, thephosphonium compound may be present in the epoxy resin composition in anamount of about 0.01 wt % to about 5 wt %, e.g., about 0.02 wt % toabout 1.5 wt % or about 0.05 wt % to about 1.5 wt %, in terms of solidcontent. Within this range, the epoxy resin composition may help secureflowability without delaying time for curing reaction.

In an implementation, the epoxy resin composition may further include anon-phosphonium curing catalyst (which does not contain phosphonium).Examples of non-phosphonium curing catalysts may include tertiaryamines, organometallic compounds, organophosphorus compounds, imidazole,boron compounds, and the like. Examples of tertiary amines may includebenzyldimethylamine, triethanolamine, triethylenediamine,diethylaminoethanol, tri(dimethylaminomethyl)phenol,2,2-(dimethylaminomethyl)phenol, 2,4,6-tris(diaminomethyl)phenol,tri-2-ethyl hexanoate, and the like. Examples of organometalliccompounds include chromium acetylacetonate, zinc acetylacetonate, nickelacetylacetonate, and the like. Examples of organophosphorus compoundsmay include tris-4-methoxyphosphine, triphenylphosphine,triphenylphosphinetriphenylborane, triphenylphosphine-1,4-benzoquinoneadducts, and the like. Examples of imidazoles may include2-methylimidazole, 2-phenylimidazole, 2-aminoimidazole,2-methyl-1-vinylimidazole, 2-ethyl-4-methylimidazole, 2-heptadecylimidazole, and the like. Examples of boron compounds may includetriphenylphosphine tetraphenyl borate, tetraphenyl borate,trifluoroborane-n-hexylamine, trifluoroborane monoethylamine,tetrafluoroborane triethylamine, tetrafluoroboraneamine, and the like.In addition, it is possible to use 1,5-diazabicyclo[4.3.0]non-5-ene(DBN), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and a phenol novolacresin salt. In an implementation, the organophosphorus compounds, theboron compounds, and the amines or imidazole curing accelerators may beused alone or in combination. Adducts obtained by pre-reacting an epoxyresin or a curing agent may be used as the curing catalyst.

In an implementation, the phosphonium compound according to anembodiment may be present in an amount of about 10 wt % to about 100 wt%, e.g., about 60 wt % to about 100 wt %, in the curing catalyst (e.g.,based on a total weight of the curing catalyst). Within this range, theepoxy resin composition may help secure flowability without delayingtime for curing reaction.

In an implementation, the curing catalyst may be present in the epoxyresin composition in an amount of about 0.01 wt % to about 5 wt %, e.g.,about 0.02 wt % to about 1.5 wt % or about 0.05 wt % to about 1.5 wt %,in terms of solid content. Within this range, the epoxy resincomposition may help secure flowability without delaying time for curingreaction.

In an implementation, the composition may further include a suitableadditive. In an implementation, the additive may include, e.g., acoupling agent, a release agent, a stress reliever, a crosslinkingenhancer, a leveling agent, and/or a coloring agent.

In an implementation, the coupling agent may include, e.g., epoxysilane,aminosilane, mercaptosilane, alkylsilane, or alkoxysilane. In animplementation, the coupling agent may be present in an amount of about0.1 wt % to about 1 wt % in the epoxy resin composition.

In an implementation, the release agent may include, e.g., paraffin wax,ester wax, higher fatty acids, metal salts of higher fatty acids,natural fatty acids, or natural fatty acid metal salts. In animplementation, the release agent may be present in an amount of about0.1 wt % to about 1 wt % in the epoxy resin composition.

In an implementation, the stress reliever may include, e.g., modifiedsilicone oil, silicone elastomers, silicone powder, or silicone resin.In an implementation, the stress reliever may be optionally present inan amount of about 6.5 wt % or less, e.g., about 1 wt % or less or about0.1 wt % to about 1 wt % in the epoxy resin composition. As the modifiedsilicone oil, a suitable silicone polymers having good heat resistancemay be used. The modified silicone oil may include about 0.05 wt % toabout 1.5 wt % of a silicone oil mixture based on the total weight ofthe epoxy resin composition, wherein the mixture may include, e.g.,silicone oil having an epoxy functional group, silicone oil having anamine functional group, silicone oil having a carboxyl functional group,and a combination thereof. If the amount of the silicone oil is greaterthan 1.5 wt %, surface contamination may occur easily and lengthy resinbleed may be encountered. If the amount of the silicone oil is less than0.05 wt %, sufficiently low modulus of elasticity may not be obtained.In addition, silicone powder having a median particle diameter of about15 μm or less may be used in that the powder does not deterioratemoldability. In an implementation, the silicone powder may be present inan amount of about 5 wt % or less, e.g., about 0.1 wt % to about 5 wt %,based on the total weight of the epoxy resin composition.

In an implementation, the additive may be present in an amount of about0.1 wt % to about 10 wt %, e.g., about 0.1 wt % to about 3 wt %, in theepoxy resin composition.

The epoxy resin composition may be curable at low temperature. Forexample, a curing initiation temperature may be about 90° C. to about120° C. Within this range, the epoxy resin composition may besufficiently cured at low temperature, thereby securing curing at lowtemperature.

In an implementation, the epoxy resin composition may have a flow lengthof about 59 inches to about 78 inches, e.g., about 71 inches to about 78inches, as measured using a transfer molding press at 175° C. under aload of 70 kgf/cm² in accordance with EMMI-1-66. Within this range, theepoxy resin composition may be used for desired applications.

In an implementation, the epoxy resin composition may have a curingshrinkage rate of less than about 0.40%, e.g., less than about 0.33% orabout 0.01% to about 0.32%, as calculated according to Equation 1.Within this range, the curing shrinkage rate is low, and the epoxy resincomposition thus can be used for desired applications.

Curing shrinkage=(|C−D|/C)×100  <Equation 1>

In Equation 1, C is a length of a specimen obtained by transfer moldingof the epoxy resin composition at 175° C. under a load of 70 kgf/cm²,and D is a length of the specimen after post-curing the specimen at 170°C. to 180° C. for 4 hours and cooling.

In an implementation, the epoxy resin composition may have a storagestability of about 85% or more, e.g., about 90% or more or about 92% ormore, as calculated according to Equation 2.

Storage stability=(F1/F0)×100  <Equation 2>

In Equation 2, F1 is a flow length (in inches) of the epoxy resincomposition measured after storing the composition at 25° C./50% RH for72 hours using a transfer molding press at 175° C. and 70 kgf/cm² inaccordance with EMMI-1-66, and F0 is an initial flow length (in inches)of the epoxy resin composition.

In the epoxy resin composition, the epoxy resin may be used alone or inthe form of adducts, such as a melt master batch, obtained bypre-reacting the epoxy resin with an additive, such as a curing agent, acuring catalyst, a release agent, a coupling agent, and a stressreliever. Although there is no particular restriction as to the methodof preparing the epoxy resin composition according to an embodiment, theepoxy resin composition may be prepared by uniformly mixing allcomponents of the resin composition using a suitable mixer, such as aHenschel mixer or a Lödige mixer, followed by melt-kneading in a rollmill or a kneader at about 90° C. to about 120° C., cooling, andpulverizing.

The epoxy resin composition according to an embodiment may be used in abroad range of applications requiring such an epoxy resin composition,e.g., in encapsulation of semiconductor devices, adhesive films,insulating resin sheets such as prepregs and the like, circuit boards,solder resists, underfills, die bonding materials, and componentreplenishing resins.

Encapsulation of Semiconductor Device

The epoxy resin composition may be used to encapsulate a semiconductordevice and may include an epoxy resin, a curing agent, a phosphoniumcompound-containing curing catalyst, inorganic fillers, and additives.

A semiconductor device according to an embodiment may be encapsulatedwith the epoxy resin composition as set forth above.

FIG. 1 illustrates a cross-sectional view of a semiconductor deviceaccording to one embodiment. Referring to FIG. 1, a semiconductor device100 according to this embodiment may include, e.g., a wiring board 10,bumps 30 on the wiring board 10, and a semiconductor chip 20 on thebumps 30. A gap between the wiring board 10 and the semiconductor chip20 may be encapsulated with an epoxy resin composition 40. The epoxyresin composition may be an epoxy resin composition according to anembodiment.

FIG. 2 illustrates a cross-sectional view of a semiconductor deviceaccording to another embodiment. Referring to FIG. 2, a semiconductordevice 200 according to this embodiment may include a wiring board 10,bumps 30 on the wiring board 10, and a semiconductor chip 20 on thebumps 30. A gap between the wiring board 10 and the semiconductor chip20 and an entirety of a top surface of the semiconductor chip 20 may beencapsulated with an epoxy resin composition 40. The epoxy resincomposition may be an epoxy resin composition according to anembodiment.

FIG. 3 illustrates a cross-sectional view of a semiconductor deviceaccording to a further embodiment. Referring to FIG. 3, a semiconductordevice 300 according to this embodiment may include a wiring board 10,bumps 30 on the wiring board 10, and a semiconductor chip 20 on thebumps 30. A gap between the wiring board 10 and the semiconductor chip20 and an entirety of a side surface of the semiconductor chip 20 (e.g.,except for the top surface) may be encapsulated with an epoxy resincomposition 40. The epoxy resin composition may be an epoxy resincomposition according to an embodiment.

In FIGS. 1 to 3, a size of each wiring board, bump and semiconductorchip, and the numbers of bumps may be modified.

In an implementation, the semiconductor device may be encapsulated withthe epoxy resin composition by low-pressure transfer molding. In animplementation, the semiconductor device may also be molded by injectionmolding, casting, or the like. The semiconductor device that may befabricated by such a molding process may include a copper lead frame, aniron lead frame, an iron lead frame pre-plated with at least one metalselected from the group consisting of nickel, copper, and palladium, oran organic laminate frame.

The following Examples and Comparative Examples are provided in order tohighlight characteristics of one or more embodiments, but it will beunderstood that the Examples and Comparative Examples are not to beconstrued as limiting the scope of the embodiments, nor are theComparative Examples to be construed as being outside the scope of theembodiments. Further, it will be understood that the embodiments are notlimited to the particular details described in the Examples andComparative Examples.

EXAMPLES Preparative Example 1 Preparation of Compound Represented byFormula 1a

34.8 g of 1,2-phenylenebis(2-hydroxybenzamide) was added to 50 g ofmethanol (MeOH), followed by adding 21.6 g of 25% sodium methoxidesolution, which in turn was completely dissolved while reacting atambient temperature for 30 minutes. To the solution, a solution of 41 gof tetraphenylphosphonium bromide (previously dissolved in 50 g ofmethanol (MeOH)) was slowly added and the mixture was allowed to furtherreact for 1 hour. The resulting white solid was filtered to remove asolvent component of the solution at low pressure, thereby obtaining 65g of a compound. The compound was identified based on NMR data as acompound represented by Formula 1a (yield: 95%).

¹H NMR (400 MHz, DMSO) 8.5 (br, 2H), 8.05-7.88 (m, 4H), 7.85-7.69 (m,18H), 7.62 (m, 2), 7.34 (t, J=12.1 Hz, 2H), 7.01-6.98 (m, 4H), 6.91 (d,J=7.2 Hz, 2H), 4.9 (s, 1H) ppm; ¹³C NMR (100 MHz, DMSO) 164.8, 159.4,137.4, 137.3, 133.6, 129.0, 128.9, 128.8, 128.2, 124.6 121.5, 119.9,116.0 ppm; ³¹P NMR (166 MHz, DMSO) 24.20 ppm; LC-MS m/z=686 (M⁺); Anal.Calcd for C₄₄H₃₅N₂O₄P: C, 76.95; H, 5.14; N, 4.08. Found: C, 76.49; H,5.43; N, 4.38.

Preparative Example 2 Preparation of Compound Represented by Formula 1b

34.8 g of 1,2-phenylenebis(2-hydroxybenzamide) was added to 50 g ofmethanol (MeOH), followed by adding 21.6 g of 25% sodium methoxidesolution, which in turn was completely dissolved while reacting atambient temperature for 30 minutes. To the solution, a solution of 43 gof (4-hydroxy-phenyl)-triphenyl-phosphonium bromide (previouslydissolved in 50 g of methanol (MeOH)) was slowly added and the mixturewas allowed to further react for 1 hour. The resulting white solid wasfiltered to remove a solvent component of the solution at low pressure,thereby obtaining 63 g of a compound. The compound was identified basedon NMR data as a compound represented by Formula 1b (yield: 91%).

1H NMR (400 MHz, DMSO) 8.5 (br, 2H), 7.94 (m, 3H), 7.82-7.66 (m, 14H),7.62 (m, 2), 7.48-7.41 (m, 2H), 7.34 (t, J=12.1 Hz, 2H), 7.11-7.09 (m,2H), 7.01-6.98 (m, 4H), 6.91 (d, J=7.2 Hz, 2H), 4.9 (s, 1H) ppm; ¹³C NMR(100 MHz, DMSO) 164.8, 159.4, 158.6, 137.7, 137.4, 137.3, 133.6, 130.0,129.0, 128.9, 128.2, 128.1, 124.6, 121.5, 120.0, 119.9, 116.0, 115.9ppm; ³¹P NMR (166 MHz, DMSO) 24.21 ppm; LC-MS m/z=702 (M⁺); Anal. Calcdfor C₄₄H₃₅N₂O₅P: C, 75.20; H, 5.02; N, 3.99. Found: C, 75.41; H, 5.36;N, 4.14.

Preparative Example 3 Preparation of Compound Represented by Formula 1c

37.5 g of 1,2-phenylenebis(2-hydroxy-4-methyl-benzamide) was added to 50g of methanol (MeOH), followed by adding 21.6 g of 25% sodium methoxidesolution, which in turn was completely dissolved while reacting atambient temperature for 30 minutes. To the solution, a solution of 41 gof tetraphenylphosphonium bromide (previously dissolved in 50 g ofmethanol (MeOH)) was slowly added and the mixture was allowed to furtherreact for 1 hour. The resulting white solid was filtered to remove asolvent component of the solution at low pressure, thereby obtaining 65g of a compound. The compound was identified based on NMR data as acompound represented by Formula 1c (yield: 92%).

¹H NMR (400 MHz, DMSO) 8.5 (br, 21-1), 8.05-7.88 (m, 4H), 7.85-7.69 (m,18H), 7.62 (m, 2), 7.34 (d, J=2.8 Hz, 2H), 6.98 (m, 2H), 6.71 (s, 2H),4.9 (s, 1H), 2.35 (s, 6H) ppm; ¹³C NMR (100 MHz, DMSO) 164.8, 159.3,143.2, 137.3, 137.2, 129.0, 128.9, 128.8, 128.2, 128.0, 124.6 121.5,116.9, 114.8, 24.6 ppm; ³¹P NMR (166 MHz, DMSO) 24.20 ppm; LC-MS m/z=714(M⁺); Anal. Calcd for C₄₆H₃₉N₂O₄P: C, 77.29; H, 5.50; N, 3.92. Found: C,77.14; H, 5.37; N, 3.99.

Preparative Example 4 Preparation of Compound Represented by Formula 1d

37.5 g of 4,5-dimethlyl-1,2-phenylenebis(2-hydroxybenzamide) was addedto 50 g of methanol (MeOH), followed by adding 21.6 g of 25% sodiummethoxide solution, which in turn was completely dissolved whilereacting at ambient temperature for 30 minutes. To the solution, asolution of 41 g of tetraphenylphosphonium bromide (previously dissolvedin 50 g of methanol (MeOH)) was slowly added and the mixture was allowedto further react for 1 hour. The resulting white solid was filtered toremove a solvent component of the solution at low pressure, therebyobtaining a compound. The compound was identified based on NMR data as acompound represented by Formula 1 d (yield: 92%).

¹H NMR (400 MHz, DMSO) 8.5 (br, 2H), 8.05-7.88 (m, 4H), 7.85-7.69 (m,18H), 7.34 (m, 2), 7.30 (s, 2H), 7.00 (m, 2H), 6.91 (d, J=2.8 Hz, 2H),5.0 (s, 1H), 2.31 (s, 6H) ppm; ¹³C NMR (100 MHz, DMSO) 164.8, 159.4,137.3, 137.2, 133.6, 132.7, 129.0, 128.9, 128.8, 125.1, 125.0, 121.5,121.4, 119.9, 116.0, 17.8 ppm; ³¹P NMR (166 MHz, DMSO) 24.20 ppm; LC-MSm/z=714 (M⁺); Anal. Calcd for C₄₆H₃₉N₂O₄P: C, 77.29; H, 5.50; N, 3.92.Found: C, 77.21; H, 5.39; N, 3.53.

Preparative Example 5 Preparation of Compound Represented by Formula Le

46.5 g of 4,5-dimethyl-1,2-phenylenebis(2-hydroxy-4-nitro-benzamide) wasadded to 50 g of methanol (MeOH), followed by adding 21.6 g of 25%sodium methoxide solution, which in turn was completely dissolved whilereacting at ambient temperature for 30 minutes. To the solution, asolution of 41 g of tetraphenylphosphonium bromide (previously dissolvedin 50 g of methanol (MeOH)) was slowly added and the mixture was allowedto further react for 1 hour. The resulting white solid was filtered toremove a solvent component of the solution at low pressure, therebyobtaining a compound. The compound was identified based on NMR data as acompound represented by Formula 1e (yield: 88%).

¹H NMR (400 MHz, DMSO) 8.71 (s, 2H), 8.5 (br, 2H), 8.27 (d, J=2.8 Hz,2H), 8.05-7.88 (m, 4H), 7.85-7.69 (m, 16H), 7.30 (s, 2H), 7.17 (m, 2H),4.8 (s, 1H), 2.35 (s, 6H) ppm; ¹³C NMR (100 MHz, DMSO) 165.5, 164.8,141.1, 137.3, 137.2, 132.7, 128.9, 128.8, 125.9, 125.1, 123.8, 120.8,116.9, 17.8 ppm; ³¹P NMR (166 MHz, DMSO) 24.20 ppm; LC-MS m/z=804 (M⁺);Anal. Calcd for C₄₆H₃₇N₄O₈P: C, 68.65; H, 4.63; N, 6.96. Found: C,68.45; H, 4.37; N, 6.53.

Preparative Example 6 Preparation of Compound Represented by Formula 1f

45.7 g of 2,3-naphthalene-bis(2-hydroxy-3-methoxy-benzamide) was addedto 50 g of methanol (MeOH), followed by adding 21.6 g of 25% sodiummethoxide solution, which in turn was completely dissolved whilereacting at ambient temperature for 30 minutes. To the solution, asolution of 41 g of tetraphenylphosphonium bromide (previously dissolvedin 50 g of methanol (MeOH)) was slowly added and the mixture was allowedto further react for 1 hour. The resulting white solid was filtered toremove a solvent component of the solution at low pressure, therebyobtaining a compound. The compound was identified based on NMR data as acompound represented by Formula 1 f (yield: 91%).

¹H NMR (400 MHz, DMSO) 8.5 (br, 2H), 8.05-7.88 (m, 4H), 7.85-7.69 (m,16H), 7.34-7.32 (m, 4H), 7.00 (m, 2H), 6.89-6.85 (m, 4H), 6.63 (s, 2H),5.0 (s, 1H), 3.73 (s, 6H) ppm; ¹³C NMR (100 MHz, DMSO) 164.8, 151.5,148.4, 137.3, 137.2, 133.7, 128.9, 128.8, 126.7, 123.0, 122.6, 121.2,120.9, 120.5, 119.1, 108.2, 56.2 ppm; ³¹P NMR (166 MHz, DMSO) 24.20 ppm;LC-MS m/z=796 (M⁺); Anal. Calcd for C₅₀H₄₁N₂O₆P: C, 75.36; H, 5.19; N,3.52. Found: C, 75.44; H, 5.37; N, 3.53.

Preparative Example 7 Preparation of Compound Represented by Formula 1g

34.8 g of 1,3-phenylenebis(2-hydroxybenzamide) was added to 50 g ofmethanol (MeOH), followed by adding 21.6 g of 25% sodium methoxidesolution, which in turn was completely dissolved while reacting atambient temperature for 30 minutes. To the solution, a solution of 41 gof tetraphenylphosphonium bromide (previously dissolved in 50 g ofmethanol (MeOH)) was slowly added and the mixture was allowed to furtherreact for 1 hour. The resulting white solid was filtered to remove asolvent component of the solution at low pressure, thereby obtaining 66g of a compound. The compound was identified based on NMR data as acompound represented by Formula 1 g (yield: 96%).

¹H NMR (400 MHz, DMSO) 8.5 (br, 2H), 8.05-7.88 (m, 5H), 7.85-7.69 (m,18H), 7.38-7.34 (m, 4H), 7.22 (m, 1h), 7.0 (m, 2H), 6.91 (d, J=7.2 Hz,2H), 5.0 (s, 1H) ppm; ¹³C NMR (100 MHz, DMSO) 164.8, 159.4, 137.3,137.2, 136.1, 133.6, 128.9, 128.8, 121.5, 119.9, 117.2, 116.0, 113.3ppm; ³¹P NMR (166 MHz, DMSO) 24.20 ppm; LC-MS m/z=686 (M⁺); Anal. Calcdfor C₄₄H₃₅N₂O₄P: C, 76.95; H, 5.14; N, 4.08. Found: C, 76.76; H, 5.22;N, 4.30.

Preparative Example 8 Preparation of Compound Represented by Formula 1h

34.8 g of 1,4-phenylenebis(2-hydroxybenzamide) was added to 50 g ofmethanol (MeOH), followed by adding 21.6 g of 25% sodium methoxidesolution, which in turn was completely dissolved while reacting atambient temperature for 30 minutes. To the solution, a solution of 41 gof tetraphenylphosphonium bromide (previously dissolved in 50 g ofmethanol (MeOH)) was slowly added and the mixture was allowed to furtherreact for 1 hour. The resulting white solid was filtered to remove asolvent component of the solution at low pressure, thereby obtaining 65g of a compound. The compound was identified based on NMR data as acompound represented by Formula 1h (yield: 95%).

¹H NMR (400 MHz, DMSO) 8.5 (br, 2H), 8.05-7.88 (m, 4H), 7.85-7.69 (m,22H), 7.34 (m, 2H), 7.0 (m, 2H), 6.91 (d, J=7.2 Hz, 2H), 5.0 (s, 1H)ppm; ¹³C NMR (100 MHz, DMSO) 164.8, 159.4, 137.3, 137.2, 133.6, 131.5,128.9, 128.8, 121.8, 121.5, 119.9, 116.0 ppm; ³¹P NMR (166 MHz, DMSO)24.20 ppm; LC-MS m/z=686 (M⁺); Anal. Calcd for C₄₄H₃₅N₂O₄P: C, 76.95; H,5.14; N, 4.08. Found: C, 76.56; H, 5.23; N, 4.44.

Details of the components used in Examples and Comparative Examples areas follows.

(A) Epoxy Resin

NC-3000 (produced by Nippon Kayaku), a biphenyl type epoxy resin, wasused.

(B) Curing Agent

HE100C-10 (produced by Air Water), a xyloc type phenol resin, was used.

(C) Curing Catalyst

Compounds (represented by Formulae 1a to 1h) prepared in PreparativeExamples 1 to 8 were used as (C1) to (C8), respectively.

(C9) A compound represented by Formula 8 was used.

(C10)

Triphenyl phosphine was used

(C11)

An adduct of triphenyl phosphine and 1,4-benzoquinone was used

(D) Inorganic Filler

A mixture of spherical fused silica having an average particle diameterof 18 m and spherical fused silica having an average particle diameterof 0.5 μm (in a weight ratio of 9:1) was used.

(E) Coupling Agent

A mixture of (e1) mercaptopropyl trimethoxy silane, KBM-803 (produced byShin-etsu Co., Ltd.) and (e2) methyl trimethoxy silane, SZ-6070(produced by Dow Corning Chemical Co., Ltd.) was used.

(F) Additive

(f1) Carnauba wax as a mold release agent, and (f2) Carbon black, MA-600(produced by Matsushita Chemical Co., Ltd.) as a coloring agent, wereused.

Examples and Comparative Examples

The components were weighed as listed in Table 1 (unit: parts by weight)and uniformly mixed using a Henschel mixer to prepare first powdercompositions. Then, each of the compositions was melt-kneaded by acontinuous kneader at 95° C., cooled, and pulverized to prepare an epoxyresin composition for encapsulation of a semiconductor device.

TABLE 1 Comparative Example Example 1 2 3 4 5 6 7 8 1 2 3 (A) 8.5 8.58.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 (B) 5.2 5.2 5.2 5.2 5.2 5.2 5.2 5.25.2 5.2 5.2 (C) C1 0.3 — — — — — — — — — — C2 — 0.3 — — — — — — — — — C3— — 0.3 — — — — — — — — C4 — — — 0.3 — — — — — — — C5 — — — — 0.3 — — —— — — C6 — — — — — 0.3 — — — — — C7 — — — — — — 0.3 — — — — C8 — — — — —— — 0.3 — — — C9 — — — — — — — — 0.3 — — C10 — — — — — — — — — 0.3 — C11— — — — — — — — — — 0.3 (D) 85 85 85 85 85 85 85 85 85 85 85 (E) (e1)0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 (e2) 0.2 0.2 0.2 0.2 0.2 0.20.2 0.2 0.2 0.2 0.2 (F) (f1) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3(f2) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Total 100 100 100 100100 100 100 100 100 100 100

(1) Flowability (inches): The flow length of each of the epoxy resincompositions was measured using a transfer molding press in a test moldat 175° C. under a load of 70 kgf/cm² in accordance with EMMI-1-66.EMMI-1-66 is a method of evaluating the molding flow of a resin toinjection or transfer molding in which the melt is injected into aspiral runner of constant trapezoidal cross section with numbered andsubdivided centimeters marked along the runner. The mold is filled froma sprue at the center of the spiral and pressure is maintained untilflow stops, the number just aft of the molded-spiral tip giving the flowdistance. A higher measured value indicates better flowability.

(2) Curing shrinkage (%): Each of the epoxy resin compositions wasmolded using a transfer molding press in an ASTM mold for flexuralstrength specimen construction at 175° C. and 70 kgf/cm² to obtain amolded specimen (125×12.6×6.4 mm). The specimen was subjected topost-molding curing (PMC) in an oven at 170° C. to 180° C. for 4 hours.After cooling, the length of the specimen was measured using calipers.Curing shrinkage of the epoxy resin composition was calculated accordingto the following Equation 1.

Curing shrinkage=(|C−D|/C)×100

In Equation 1, C is the length of the specimen obtained by transfermolding of the epoxy resin composition at 175° C. under a load of 70kgf/cm², and D is the length of the specimen after post-curing thespecimen at 170° C. to 180° C. for 4 hours and cooling.

(3) Glass transition temperature (° C.): Glass transition temperature ofeach of the epoxy resin compositions prepared in the Examples andComparative Examples was measured using a thermomechanical analyzer(TMA). Here, the TMA was set to heat the resin composition at a rate of10° C./min from 25° C. to 300° C.

(4) Moisture absorption (%): Each of the resin compositions prepared inthe Examples and Comparative Examples was molded at a mold temperatureof 170° C. to 180° C., a clamp pressure of 70 kg/cm², a transferpressure of 1,000 psi and a transfer speed of 0.5 cm/s to 1 cm/s for acuring time of 120 sec to obtain a cured specimen in the form of a dischaving a diameter of 50 mm and a thickness of 1.0 mm. The specimen wassubjected to post-molding curing (PMC) in an oven at 170° C. to 180° C.for 4 hours and allowed to stand at 85° C. and 85% RH for 168 hours. Theweights of the specimen before and after moisture absorption weremeasured. Moisture absorption of the resin composition was calculatedaccording to the following Equation 3.

Moisture absorption (%)=[(Weight of the specimen after moistureabsorption−Weight of the specimen before moisture absorption)+(Weight ofthe specimen before moisture absorption)]×100

(5) Adhesive strength (kgf): A copper metal device having a size adaptedto a mold for adhesive strength measurement was prepared as a testpiece. Each of the resin compositions prepared in the Examples andComparative Examples was molded on the test piece at a mold temperatureof 170° C. to 180° C., a clamp pressure of 70 kgf/cm², a transferpressure of 1,000 psi, and a transfer speed of 0.5 cm/s to 1 cm/s for acuring time of 120 sec to obtain a cured specimen. The specimen wassubjected to post-molding curing (PMC) in an oven at 170° C. to 180° C.for 4 hours. The area of the epoxy resin composition in contact with thespecimen was 40±1 mm². The adhesive strength of the epoxy resincomposition was measured using a universal testing machine (UTM). 12specimens of each composition were produced. After the measurementprocedure was repeated, the measured adhesive strength values wereaveraged.

(6) Degree of cure (Shore-D): Each of the epoxy resin compositions wascured using a multi-plunger system (MPS) equipped with a mold at 175° C.for 50 sec, 60 sec, 70 sec, 80 sec, and 90 sec to construct exposed thinquad flat packages (eTQFPs), each including a copper metal device havinga width of 24 mm, a length of 24 mm and a thickness of 1 mm. Thehardness values of the cured products in the packages on the moldaccording to the curing periods of time were directly measured using aShore D durometer. A higher hardness value indicates better degree ofcure.

(7) Storage stability (%): The flow length (in inches) of each of theepoxy resin compositions was measured in accordance with the methoddescribed in (1) while storing the compositions for 3 days in athermo-hygrostat set to 25° C./50% RH and measuring every 24 hours.Percent (%) of the flow length after storage to the flow lengthimmediately after preparation of the composition was calculated. Ahigher value indicates better storage stability. Storage stability after72 hours of the epoxy resin composition was calculated according to thefollowing Equation 2.

Storage stability=(F1/F0)×100

(wherein F1 is the flow length (in inches) of the epoxy resincomposition measured after storing the composition at 25° C./50% RH for72 hours using a transfer molding press at 175° C. and 70 kgf/cm² inaccordance with EMMI-1-66, and F0 is the initial flow length (in inches)of the epoxy resin composition.)

(8) Reliability: Each of the eTQFP packages for the evaluation offlexural properties was dried at 125° C. for 24 h. After 5 cycles ofthermal shock testing (1 cycle refers to a series of exposures of thepackage to −65° C. for 10 min, 25° C. for 10 min, and 150° C. for 10min), the package was allowed to stand at 85° C. and 60% RH for 168hours and treated by IR reflow three times at 260° C. for 30 sec(preconditioning). After preconditioning, the occurrence of externalcracks in the package was observed using an optical microscope, and theoccurrence of peeling between the epoxy resin composition and a leadframe was evaluated by scanning acoustic microscopy (C-SAM) as anon-destructive test method. External cracks of the package or peelingbetween the epoxy resin composition and the lead frame mean thatreliability of the package cannot be guaranteed.

TABLE 2 Comparative Example Example Evaluation item 1 2 3 4 5 6 7 8 1 23 Basic Flowability (inch) 75 71 74 73 78 77 76 74 66 52 58 physicalCuring shrinkage (%) 0.31 0.32 0.31 0.32 0.31 0.32 0.31 0.32 0.34 0.420.40 properties Glass transition temp. (° C.) 123 123 124 124 123 124123 123 123 121 122 Moisture absorption (%) 0.25 0.25 0.24 0.24 0.250.24 0.25 0.25 0.24 0.25 0.26 Adhesive strength (kgf) 77 74 75 76 76 7777 77 74 72 74 Evaluation Degree of 50 sec 72 72 71 71 71 72 71 71 74 7274 of cure (Shore- 60 sec 74 73 73 73 72 73 72 73 73 60 64 packages D)according 70 sec 76 75 76 75 78 74 75 75 76 64 66 to curing 80 sec 77 7777 77 78 77 76 76 76 67 70 time 90 sec 78 78 78 78 79 77 77 77 76 67 71Storage 24 hr (%) 98 97 98 97 98 98 98 98 92 90 92 stability 48 hr (%)94 95 94 92 96 95 94 94 89 84 88 72 hr (%) 92 93 92 93 93 94 92 92 84 7479 Reliability Number of 0 0 0 0 0 0 0 0 0 0 0 packages sufferingcracking Number of 0 0 0 0 0 0 0 0 5 45 20 packages suffering peelingNumber of tested 88 88 88 88 88 88 88 88 88 88 88 semiconductors

It may be seen that the epoxy resin compositions prepared in Examples 1to 8 had higher flowability and higher degree of cure (even with shortercuring times) in view of curability for each curing period of time thanthe epoxy resin compositions of Comparative Examples. For storagestability, it may be that the epoxy resin compositions of Examples 1 to8 showed less change in flowability after 72 hours of storage. Further,it may be seen that the epoxy resin compositions of Examples 1 to 8 didnot suffer from cracking and thus had excellent crack resistance and didnot suffer from peeling and thus had excellent moisture resistancereliability.

The compositions of Comparative Examples 1 to 3 (not including thephosphonium compound according to an embodiment) had low flowability andhigh curing shrinkage, had low curability for each curing period oftime, and low storage stability when used in a package, and sufferedfrom peeling and thus exhibited poor moisture resistance reliability.Therefore, it may be seen that the compositions of Comparative Examples1 to 3 could not ensure desired effects.

By way of summation and review, with the trend toward compact,lightweight and high performance electronic devices, high integration ofsemiconductor devices has been accelerated year by year. Some issues mayarise with increasing demand for surface mounting of semiconductordevices. Some desirable features of packaging materials forsemiconductor devices may include rapid curability to improveproductivity and storage stability to improve handling performanceduring distribution and storage.

The embodiments may provide a compound for curing catalysts having highstorage stability, which is capable of accelerating curing of an epoxyresin and curing of an epoxy resin at low temperature while minimizingviscosity change in a mixture including the compound, an epoxy resin, acuring agent and the like even within desired ranges of time andtemperature, thereby ensuring that the epoxy resin composition obtainedafter curing at high temperature does not exhibit any deterioration inmoldability, mechanical, electrical, and chemical properties of moldedproducts due to decrease in flowability; an epoxy resin compositionincluding the same; and a semiconductor device encapsulated with theepoxy resin composition.

The embodiments may provide a compound for curing catalysts capable ofaccelerating curing of an epoxy resin, having good flowability uponmolding and high curing strength, and capable of being rapidly cured.

The embodiments may provide a compound for curing catalysts capable ofaccelerating curing of an epoxy resin at low temperature.

The embodiments may provide a compound for curing catalysts having highstorage stability, which can catalyze curing only at a desired curingtemperature without exhibiting any curing activity at a temperaturedeviating from the desired curing temperature.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

What is claimed is:
 1. A phosphonium compound represented by Formula 1:

wherein: R₁, R₂, R₃, and R₄ are each independently a substituted orunsubstituted C₁ to C₃₀ aliphatic hydrocarbon group, a substituted orunsubstituted C₆ to C₃₀ aromatic hydrocarbon group, or a substituted orunsubstituted C₁ to C₃₀ hydrocarbon group including a hetero atom; X andY are each independently a substituted or unsubstituted C₆ to C₃₀arylene group, a substituted or unsubstituted C₃ to C₁₀ cycloalkylenegroup, or a substituted or unsubstituted C₁ to C₂₀ alkylene group; R₅and R₆ are each independently hydrogen, a hydroxyl group, a C₁ to C₂₀alkyl group, a C₆ to C₃₀ aryl group, a C₃ to C₃₀ heteroaryl group, a C₃to C₁₀ cycloalkyl group, a C₃ to C₁₀ heterocycloalkyl group, a C₇ to C₃₀arylalkyl group, or a C₁ to C₃₀ heteroalkyl group.
 2. The phosphoniumcompound as claimed in claim 1, wherein R₁, R₂, R₃, and R₄ are eachindependently a substituted or unsubstituted C₆ to C₃₀ aryl group. 3.The phosphonium compound as claimed in claim 2, wherein at least one ofR₁, R₂, R₃, and R₄ is a hydroxyl group-substituted C₆ to C₃₀ aryl group.4. The phosphonium compound as claimed in claim 1, wherein thephosphonium compound is represented by one of the following Formulae 1ato 1h.


5. A method of preparing a phosphonium compound, the method comprisingreacting a phosphonium cation-containing compound represented by Formula2 with a phenylene-bis-benzamide anion-containing compound representedby Formula 3:

wherein, in Formula 2, R₁, R₂, R₃, and R₄ are each independently asubstituted or unsubstituted C₁ to C₃₀ aliphatic hydrocarbon group, asubstituted or unsubstituted C₆ to C₃₀ aromatic hydrocarbon group, or asubstituted or unsubstituted C₁ to C₃₀ hydrocarbon group including ahetero atom, and M is a halogen, and wherein, in Formula 3, X and Y areeach independently a substituted or unsubstituted C₆ to C₃₀ arylenegroup, a substituted or unsubstituted C₃ to C₁₀ cycloalkylene group, ora substituted or unsubstituted C₁ to C₂₀ alkylene group; R₅ and R₆ areeach independently hydrogen, a hydroxyl group, a C₁ to C₂₀ alkyl group,a C₆ to C₃₀ aryl group, a C₃ to C₃₀ heteroaryl group, a C₃ to C₁₀cycloalkyl group, a C₃ to C₁₀ heterocycloalkyl group, a C₇ to C₃₀arylalkyl group, or a C₁ to C₃₀ heteroalkyl group; and Z is an alkalimetal or Ag.
 6. An epoxy resin composition, comprising: an epoxy resin,a curing agent, an inorganic filler, and a curing catalyst, wherein thecuring catalyst includes the phosphonium compound as claimed in claim 1.7. The epoxy resin composition as claimed in claim 6, wherein the epoxyresin includes at least one of a bisphenol A epoxy resin, a bisphenol Fepoxy resin, a phenol novolac epoxy resin, a tert-butyl catechol epoxyresin, a naphthalene epoxy resin, a glycidylamine epoxy resin, a cresolnovolac epoxy resin, a biphenyl epoxy resin, a linear aliphatic epoxyresin, a cycloaliphatic epoxy resin, a heterocyclic epoxy resin, a spiroring-containing epoxy resin, a cyclohexane dimethanol epoxy resin, atrimethylol epoxy resin, and a halogenated epoxy resin.
 8. The epoxyresin composition as claimed in claim 6, wherein the curing agentincludes a phenol resin.
 9. The epoxy resin composition as claimed inclaim 6, wherein the curing agent includes at least one of a phenolaralkyl phenol resin, a phenol novolac phenol resin, a xyloc phenolresin, a cresol novolac phenol resin, a naphthol phenol resin, a terpenephenol resin, a polyfunctional phenol resin, a dicyclopentadiene-basedphenol resin, a novolac phenol resin synthesized from bisphenol A andresorcinol, a polyhydric phenolic compound, an acid anhydride, and anaromatic amine.
 10. The epoxy resin composition as claimed in claim 6,wherein the curing catalyst is present in the epoxy resin composition inan amount of about 0.01 wt % to about 5 wt %, in terms of solid content.11. The epoxy resin composition as claimed in claim 6, wherein thephosphonium compound is present in the curing catalyst in an amount ofabout 10 wt % to about 100 wt %, based on a total weight of the curingcatalyst.
 12. The epoxy resin composition as claimed in claim 6, whereinthe epoxy resin composition has a curing shrinkage rate of less thanabout 0.40%, as calculated according to Equation 1:Curing shrinkage=(|C−D|/C)×100  Equation 1 wherein, in Equation 1, C isa length of a specimen obtained by transfer molding the epoxy resincomposition at 175° C. under a load of 70 kgf/cm², and D is a length ofthe specimen after post-curing the specimen at 170° C. to 180° C. for 4hours and cooling.
 13. The epoxy resin composition as claimed in claim6, wherein the epoxy resin composition has a storage stability after 72hours of about 85% or more, as calculated according to Equation 2:Storage stability=(F1/F0)×100  Equation 2 wherein, in Equation 2, F1 isa flow length in inches of the epoxy resin composition, measured afterstoring the composition at 25° C./50% RH for 72 hours, using a transfermolding press at 175° C. and 70 kgf/cm² in accordance with EMMI-1-66,and F0 is an initial flow length in inches of the epoxy resincomposition.
 14. A semiconductor device encapsulated with the epoxyresin composition as claimed in claim 6.